<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script type="text/javascript">
		var str = 'hello wolrd';
		var arr = ['a','b','c','d'];
		console.log(str.length);
		console.log(str.substr(0,5));
		console.log(str);

		console.log(arr.join('|'));
		console.log(str.split(''));

	</script>
</head>
<body>
	<script type="text/javascript">
		var arr = ['a','b','c','d'];
		for(var i=0; i<arr.length;i++){
			alert(arr[i]);
		}

		var obj = {name:'zhaosi',age:50,height:175};
		for(var k in obj){
			// alert(k);
			console.log(obj[k]);
		}

	</script>
</body>
</html>